Vhf z-coil plasma source

Abstract

A VHF Z-coil semiconductor processing plasma source uses Inductively Coupled Plasma (ICP) and has a Z-shaped coil wound about a chamber in two interconnected turns. High frequency RF electric power of from 40 MHz to 120 MHz is supplied by a power source to the coil. A process gas introduced into the chamber is energized by the coil and generates plasma ions of high density suitable for semiconductor dry etching.

What is claimed is: 
     
         1 . A Very High Frequency (VHF) Z-coil plasma source for generating and injecting plasma using Inductively Coupled Plasma (ICP), the VHF Z-coil plasma device comprising:
 a chamber for receiving a process gas for the generation of plasma and for injecting the generated plasma;   a Z-shaped coil wound on the chamber in two horizontal, interconnected conductor turns; and   a high frequency RF power source for generating electric power of 40 MHz to 120 MHz to be applied to the Z-shaped coil to generate the plasma from the process gas within the chamber.   
     
     
         2 . The VHF Z-coil plasma source of  claim 1 , wherein the chamber comprises in vertical alignment from the top down:
 a mixing zone for mixing the process gas;   a generation zone for generating the plasma upon excitation of the process gas by the electric power applied to the Z-shaped coil;   an acceleration zone for accelerating the generated plasma; and   a diffusion zone for diffusing the accelerated plasma.   
     
     
         3 . The VHF Z-coil plasma source of  claim 2 , wherein the first conductor turn of the coil is disposed about the generation zone and the second conductor turn is disposed about the acceleration zone. 
     
     
         4 . The VHF Z-coil plasma source of  claim 2 , wherein one or more diffusion plates for efficiently diffusing the process gas before and after plasma generation are disposed at lower portions of the mixing zone and the diffusion zone. 
     
     
         5 . The VHF Z-coil plasma source of  claim 4 , wherein the diffusion plate is formed of at least one of ceramics, quartz, silicon carbide (SiC), sapphire, and aluminum. 
     
     
         6 . The VHF Z-coil plasma source of  claim 1 , wherein the coil has a vertical conductor interconnecting the first and second conductor turns. 
     
     
         7 . The VHF Z-coil plasma source of  claim 1 , wherein one or more supply pipes for supplying the process gas are connected to an upper portion of the chamber. 
     
     
         8 . The VHF Z-coil plasma source of  claim 1 , wherein the chamber has a cylindrical shape. 
     
     
         9 . The VHF Z-coil plasma source of  claim 8 , wherein a diameter of the chamber is 5 cm to 10 cm. 
     
     
         10 . The VHF Z-coil plasma source of  claim 8 , wherein a height of the chamber is 10 cm to 15 cm. 
     
     
         11 . The VHF Z-coil plasma source of  claim 1 , wherein the chamber is formed of at least one of ceramics, quartz, silicon carbide (SiC) and sapphire. 
     
     
         12 . The VHF Z-coil plasma source of  claim 1 , further comprising a chuck disposed beneath the chamber for receiving a semiconductor wafer thereon, whereby the distance between a wafer disposed on the chuck and the chamber is 3 cm to 10 cm. 
     
     
         13 . The VHF Z-coil plasma source of  claim 12 , wherein a length of the chuck is 20 cm to 40 cm.